The present disclosure relates to the provision of further performance capability on a gas turbine engine by integrating a constant-speed device into a combined environmental control system and thermal management air system.
Gas turbine engines may use air-driven systems to manage engine temperature as part of a thermal management system (TMS) and to provide high pressure air for use in the passenger cabin via an environmental control system (ECS). TMS systems use heat exchangers to reject internal heat to the engine's surroundings. As fan pressure ratio drops as a result of engine designs, heat exchangers may become prohibitively large in size and weight and as a result require considerable valuable packaging volume.
ECS air is provided by bleed ports on the engine, for example, on the high pressure compressor. This use of bleed ports may result in performance loss. ECS air is routed through a series of pipes and valves, then through a pre-cooler near the top of the engine/aircraft interface to cool the air prior to entry into the aircraft wing, and then through the aircraft air cycle machine (ACM) for use in the cabin.